Fluid operated mechanism



Nov. 2s, 1944. H. SHAFF 2,364,004

FLUID OEERAIED MECHANISM Filed NDV. 5, 1942 v /zvefzor' @cned/516km# .and the other rigid with the crank plate.

Patented Nov. 28, 1944 at Ernest H. Sha, Spring Lake, Mich., assignor to Keller Tool Company. a corporationof Michigan Application November 3, 1942, serial No. 464,339 `9 Claims. (Cl. 14T-60) The invention pertains to fluid operated motors or like mechanisms of the `type disclosed in my prior Patent No. 1,781,132, issued November 11,

i `1930, and in that instance applied to the operation of a portablexpressure fluid actuated tool.. I `As disclosed in said patent, the mechanism comprises a shaft mounted coaxially` of an annular casing and having a crank arm rigid with and inclined relativefthereto so Athat `in `the rotation A crank `.plate journaled on the axis of the crank arm is x mounted for rocking or wobbling motion under p the action of a series of pressure fluid actuators of the shaft the arm describes a cone.

consisting of cylinders and pistons operatively connected with the crank plate at circumferenr tially spaced points. The plate being held against rotation, a wobbling motion isimparted theretoI A through the successive operation of the actuators,

and such motion is transmitted through the `crank p larm to a driven shaft carrying `the tool to be:

operated.

The present invention concerns primarily a motion transmittingmechanism having an improved means for holding the crank plate against rotationwhile permitting the `aforesaid wobbling motion, to the end that the emciency of the i001 maybe increased substantially. p

In my prior patent, `the means forholding the crank plate against rotation comprises `two standard intermeshing bevel gears, one being astationary gear mounted on the axis of the shaft The use of standard bevel gearing involved the adoption of pitch cone angles conforming accurately to the relative angulardisposition of the axes'of the gears and this in turn `necessitated the disposition of the crank plate forwardly along the axis `of the crank arm. Asa result, the center of I gravity of the plate and the parts carried thereby was offset `in the same direction relative to the `axis of the shaft as the crank arm itself. `The primaryobject of the present invention is to `provide an improved construction and arrangement with the center of gravity of the crank plate and parts thereon offset from the axis of the `shaft but in a direction opposite the crank arm wherebyto compensate in large measure for the out-of-balance condition inherent in the employment of a crank arm.

`Another object is to provide an improved form of gearing for holding the crank plate against rotation `during the wobbling motion, such that the necessity for strict adherence to certain pitch g `cone angles is avoided.

`In the accompanying drawing, wherein `I have illustrated a preferred embodiment of my invenp tion: I

Figure 1 is a longitudinal sectional View par-` tially in elevation, showing a pressure `fluid actuated tool embodying my invention.` I I I Fig. 2 is atransverse sectional view taken in theplane ofline 22 of Fig.` 1 (same as `II---II of the patent, but looking in the opposite direcl tion) I Fig. 3 is an elevational view of thefcrankplate detached and embodying` one `of the gearelements.

I shaft Referring erst to Fig. for the drawing, the `tool shown `by wayof illustration comprises `an annular casing -1 having a central bearing 8 in which is fixed a sleeve 9 rotatably receiving a I0. A plurality of pressure fluid actuators, herein five,A are mounted in circumferential i series in the casing about the axis of the shaft I0.

Each comprises a cylinder II and `a `piston ,|2. i

Under the control `of suitable Valve mechanism `forming no` part of the present invention and .n therefore not herein shown, the pistons are actu-` plate or spider (Fig. 3) `supported upon the crank annulus 22 of the spider (Fig. 3).

` observed that the two sets of bearing balls are thus disposed at opposite ends of a'bearing sleeve member-I3 journaled about the axis of a crank arm I4 rigid with the shaft I0 and inclined relative thereto, the angleof inclination being, in

`the present instance, about `thirty degrees.

The thrustmember constitutes a part ofthe improved motion transmitting'mechanism of the present invention.` As in the case of said prior patent, the memberembodies a series of cranks for successive cooperation with the crank arm I4 on theshaft as set forth in said prior patent. Herein the member is in the form of a skeleton arm through the medium of two sets of bearing yballs respectively designated generally I5 and I6.

The balls I5 engage an inner race I'I integral with the forward end` of the crank arm I4 and an outer race I8 formed ona bushing I9` which is screw threaded into a cylindrical hub 20 of the spider I3. The bearingballs I6 engage with an inner raceway 2| formed atthe base of the crank arm I4 and an outer raceway formed in a central projecting forwardly from the annulus-22 and formed bythe hub 20 of the annulusand the intertting bushing I9. Axially alined with the shaft I0 and formed integral with the forward end of the crank arm is a tubular member 23 suitably supported in the forward wall of the casing I by means including a ball bearing 24. .I

`ated to impart successive impulses to `a thrustA It will `be 2,364,004 51j [gli l The circumferentially arranged actuators imjournaled on the axis of said crank arm and a part their successive thrusts to the spider I3 plurality of radial arms integral with said annulus through the medium of connecting rods 25 having and cooperating to form a circular rack, a staspherical heads at opposite ends respectively tionary gear element mounted on the axis of rotasocketed in the pistons I2 and in the periphery 5 tion of said shaft and meshing with said rack to of the spider. As successive impulses are transhold said member against rotation, and means mitted to the spider, it is held against rotation for imparting a Wobbling motion to said member by twollcoacting gearlelements .respectively rigid and. a,rotarymotionto..sai 5ll shaft .comprising a with the stationary sleevel 9 andi'the'icrank plate. series of-'actuators disposedlabout'theaxis of the The present'invention concerns the construc- 10 shaft and operatively Yconnected with certain of tion and arrangement of these cooperating gear .l the arms of said spider. l

elements, and more particularly in the use of a 2. A fluid operated mechanism comprising, in rack type gear element formedf-'inwthis-Ieinbbdifftcoinbiriation a casing having a circular series of ment by making the thrustmemberinthe form f cylinders disposeddn parallel relation about a of a spider. Thus the spidertcompris es,.,inaddi-il5-tcentral-axis,T a's-h'ait rotatably mounted on said tion to the central annulus 22, a plurality of arms axis, pistons inlsaid cylinders, a crank arm rigid 26, one for each of the actuators, the'outer ends with said shaft and inclined relative thereto, a of the arms being formedwi-th'so'ckets"121-^ to"re A "fskeletonfcra'nk" plate having a central annulus ceive the bearing balls of the connecting rods 25.r ...Journaled on said crank arm, rods connecting'said In addition to the arms 26, the spider comprises 20 pistons with said crank plate at circumferentially a'series of short rarms'23 arranged midWay-bef"spaced-'points, a-nonrotary bevelgear element tween the longer arms 26 and forming with'the `disposed'fon1the axis of said shaft, said annulus inner end Yportions of-'thelong armsthe teeth f--'havin`g"integ1"a1"ftherewith a 'plu-ality' C'fi'mS 'Voi a circular rack-'generallydesignated l29.` Co- `-""v`vit1f1 'which said'r'ods are connected,and'inter acting with thisf'ra'ck is a stationarybevel gear-fl gs'svning short arms also'integral with theannulus element forme'dbyan annular seriesv of-Lteeth 29' *tand'fcooperati-ng With'the rst mentioned'armsto 'i integral with the for-wardend of the sleeve 9. feroz-m acircular rack lmeshing Withsaid station- =As'first.above-set forth, in'the'prior construcefaryfge'arelement. v l f tion, the gear element corresponding to the'ciri 3:A lfluid operated mechanism comprisingffin cular rackf'was in the form-'of ai standard bevel-iaof-icombination, a rotatably mounted shaft, afcrank l'--fgear which' made it necessarythat thegear elearm rigidfwith Vthe shaftA and inclinedl relative ment occupy a position along the crankarm I4 ffth'eretog a rvc1vank-1plate journaled on theaxisof iadvancedfrom the baseofthe arrnito'fsuch an if'the-crankiarm'vand dispos'ed'substantiallyat'fthe 'f'exte'ntthat thefcenter' of gravityv of the crank" @bas there'ofltwo Cooperating gem.,elementsv one "iplate assembly Wasfoffs'etv relative to `the axis"of''frigid-Withlthecrankplate `and theiothe `iixed the'shaft I0 in the s'ame'd-irection as the Acrank 'lfaboutltheaxisfof said shaft,- one of saidlgearele- ""farrn. I have' found that bytheuse of a circular ff-mentslfbeingintthe*form "of a circular rack,` a f rack inv the placeof the standard type'bevelgear, Lseriesiof cylindersf"disposed v'about "the axis-fof strich-adherence tOcertain-deflnite-pitoh cone -`'Usaid"sh'aft,vfandn pis-tons in saidcylindershaving angles islavoided andthe plate lmay-`occupy aiilo! thrust ballsl'connect'ed with said crank plate 'at 1 -position relativeto'lthecrank arm such that the circumferentially spaced points, said'r'ack'being Jcenterof grav-ityp the assemblyisoffset-relative disposed substantially-inthe same'plane as the to-the'axis ofy the shaft in a'direction'opposite to licent'ersof-said'thrust balls. @that of the crank'armjthereby compensatingin 4':'-A'l1df\0perated mechanism COIIIDISIllH 'flarge'part for the out-of-balance condition'-incieegicoinbinationa rotatably mounted shaftehaving 41'd'en-,ftoth'e useof a crank-arm.,A In this connecr-`aniriclin'ed crank arm; al thrust; member jour- *'tio-itwillbebbserved'thattheiarmslZG and-"28 lnaled on said 'arrrrfahd-*comprising a' central project radially irom'the'annulus and arethererParrr1'1.11us'forming a bearing'and having integral fore disposed substantiallyinlthe-plane*of the itherewith ase-ries off circumferentially 4spaced rearsetfof bearingballsvr I6. Thebearingsleevero' crank 'arms-and intermediate arms cooperating =-projecting'"forwardlyfrom t-he'fannulus isfcom- ".tHform a circular rack, a non-rotarylbevel gear 'deposed-simply of the hub portionl'ZIl and Ibushing inmounted-ion'fthe axis of 'saidlshaft 'and a series l ISlYand is accordingly' of comparatively` light "-of actuators Vres}; e'c'tively connected ytothecrank l'weight-c'onstructiorr` "Thus thecenterof'gravity tiarmsofsaidthrust'rmember. f

of theentire thrustmember is shifted^rearwardlye55 5:1 lrlfluidl operated mechanism'"comprising-in `-*With-theresulttliatthe rearfset of-bearing balls Ifcombiriatiomv a1circular=\=series fof"cylinder fand #may/bev disposedon a centerofset from the axis Valpiston units each-'comprising a'piston* r'odf with a of'theshaftf'lll 'in a direction Aopposite'the-*crank fthrustffball-orrits outer/end, a centrally mounted Aiarml'Ill.-"As ares'ult, Ihavel beenvable izo-:reduce "iishaft' havingfan'inc'lined "crankarm rigidlthere- '-fvery substantially the amount fof vibration-withf-ffofivith, a' stati'onaryfmemberA providingfan annular 'f a-consequent increasein thef'eiciencyof the'tool seriesPoflb'evel gear-'-teeth "encirclin'g--s'aid shaft, fbyapproximatelyftwenty percent."fMoreoverflby .y lthrust*member, "and ball bearing*1means'sup l'the use of a skeleton crank plate orspider of'the 'rlfportingsaid memberionlsaidcrankarm saidsh'aft rltypehereinr employed, ithasebeen *possible Ato )'ihavingiarri-nner*ball race formed integralltherefz-through-'the grease whichI inuse ispa'c-ked -inf the svferentially spacedcrank arms'c'onn'e'ctedWithfsaid p waging piston rods and forming sockets -for coaction with z' Iaclaim as my invention; Pffmsthe .thrustaballsfonsaidrodsfand a ser-iesofinterpiston units each comprising a piston rod with a thrust ball on its outer end, a centrally mounted shaft having an inclined crank arm rigid therewith, a stationary member providing `an annular series of bevel gear teeth encircling said shaft,

e thrust member on said crank arm including a series of bearing balls interposed between the annulus and the crank arm at the base thereof, said rack, bearing balls and thrust balls being disposed substantially in a common plane. l

7. A crank unit for a fluid operated mechanisrm having a circular series of pistons, a centrally mounted shaft with an inclined crank* arm thereon and a central stationary'gear element, said unit comprising an annulus forming a central bearing member and having integraltherewith a series of circumferentially spaced crank arms for connection with said pistons and intermediate relatively short arms cooperating with the crank arms to form a circular rack for coac tion with said stationary gear element.

`8. A motiontransmitting mechanism of the character set forth comprising, in combination, a rotatably mounted shaft, a crank arm rigid with the shaft and inclined relative to the axis thereof, a thrust member having a central annulus, a bearing sleeve rigid with and projecting forwardly fromsaid annulus in encircling relationto said'crank arm, two sets of bearing balls interposed between said crank arm and said ing rods, a thrust member having a central an` sleeve at opposite ends of the latter, the rear set of balls being arranged in a circular series between the annulus and the base of the crank arm upon a center offset relative to the axis of said shaft on the side thereof opposite the crank arm, a stationary bevel gear element mounted. on the axis of rotation ofthe shaft with its pitch circle disposed in a plane perpendicular to the axis of the shaft, and a series of arms projecting radially from said annulus and forming a circular rack meshing with said bevel gear element to hold the thrust member against rotation."

9. A fluid operated mechanism comprising, in combination, a'rotatably mounted shaft, a crank arm rigid with the shaft and inclined relative to the axis thereof, a plurality of cylinders arranged in a circular series about said shaft, pistons in said cylinders having forwardly extendnulus with a plurality of radial thrust arms connected at their outer ends to the forward ends of the piston` rods, a bearing sleeve rigid `with and projecting forwardly from said annulus in encircling relation to the crank arm, two sets of bearing balls interposed betweensaid crankarm and said sleeve at opposite ends of the latter, the rear set of balls being arranged in a circular series between the annulus and the base of the crank arm, a stationary bevel gear element coaxial with said shaft, and a series of arms projecting radially from said annulus intermediate the thrust arms and coacting therewith to form a circular rack meshing with said bevel gear element to hold the thrust member against rotation.

ERNEST H. SHAFF. 

